Download the Windows 8 Developer Preview from the follow link http://msdn.microsoft.com/en-us/windows/apps/br229516. Choose your version.
Download and install Oracle VirtualBox.
- Launch VirtualBox and create a New virtual machine (VM).
- Create a new VM with Windows 8 Developer Preview OS. Next
- Select at least half the RAM on your machine. Next
- Create a new Hard Drive. Next
- Select VDI (VirtualBox Disk Image). Next
- Select Dynamically Allocated. Next
- Set the position and the size (a minimum of 80GB is required) of the Virtual Drive. Next
- A new empty Virtual Machine was created.
To install the relative OS load the .iso image on a virtual optical device in the guest machine.
- Open VirtualBox and launch the Virtual Machine created before
- Follow the procedure of the first start
- Choose the installation support (the virtual optical device where you loaded the .iso image
- Wait until the OS installation is finished